In rotary electric machines that are configured such that a stator coil is cooled by a frame being cooled, thermal resistance between a stator core and the stator coil is high, and coil temperature increases during heavy loads. Thus, because output is limited or the apparatus is increased in size in order to prevent the coil temperature from exceeding an upper temperature limit, one problem has been that power density is reduced.
Conventionally, in answer to problems of this kind, methods have been disclosed to improve the power density by adopting a configuration in which a ring-shaped groove is disposed at a load side of a load-side bracket that is adjacent to a stator, a ceramic film is disposed therein, and then end portions of windings that are wound into the stator core are inserted into the ring-shaped groove, enabling heat generated in windings also to be radiated through the load-side bracket in order to reduce the coil temperature (see Patent Literature 1, for example).